1. Field of the Invention
This invention generally relates to a semiconductor circuit, and, in particular, to a semiconductor integrated circuit, such as LSI, provided with a test mode activation circuit.
2. Description of the Prior Art
A semiconductor circuit typically includes a particular input terminal to which a voltage having a predetermined level is applied to establish a test mode condition. For this reason, it is relatively easy to establish a test mode; however, there is a possibility of inspecting the internal information which can be observed externally only when the test mode is established. In particular, in a one-chip microcomputer including a ROM whose program may be damped during test mode, the program may be read out by setting the test mode quite easily. This is disadvantageous because the program stored in the ROM is easily accessible.